I am a Microsoft C# MVP, author, speaker, blogger, developer, and creator of WP Requests and WinStore Requests.
I've been involved with computers in one way or another for as long as I can remember, but started professionally in 1993. Although my primary focus right now is commercial software applications, I prefer building infrastructure components, reusable shared libraries and helping companies define, develop and automate process and code standards and guidelines.

Microsoft today announced the new product line for Windows 7. In some ways the new Windows 7 product line follows the same ideas of Windows Vista, but the big differences are that each Windows 7 edition is a superset of the previous edition (which means that each higher edition will have every feature of all lower editions) and they will be focusing primarily on two editions of Windows 7: Windows 7 Home Premium and Windows 7 Professional.

The breakdown on the different editions is:

Windows 7 Starter

This is for price-sensitive customers with small notebooks PCs.

Key Feature list:

Broad app and device compatibility with up to 3 concurrent applications

Decrease time branch office workers wait to open file across the network with BranchCache (requires Windows Server 2008 R2)

Prevent unauthorized software from running with AppLocker

Windows 7 Ultimate

Key Feature list:

Enterprise features

Unlimited applications

Multi-language packs

I know that looks like there are still a lot of different editions, but the key points are:

For Consumers: Microsoft recommends Windows 7 Home Premium for most customers and Windows 7 Professional for customers who want additional features and functionality useful for small business activities.

For Businesses: Microsoft recommends Windows 7 Professional for most customers and Windows 7 Enterprise for medium-to-large business and enterprise customers that choose to license Windows through Software Assurance.

The features in each version of Windows 7 build upon the one before it. As customers move up from one edition to the next, from Windows 7 Starter through Windows 7 Ultimate, they gain additional features and lose none.